Birds nesting under your solar panels: what you may remove, when, and what exclusion costs

What 16 U.S.C. 703 says about nests, word for word

The Migratory Bird Treaty Act puts its prohibition in a single sentence, and nests are named in it. Section 703(a), in the 2024 edition of the U.S. Code, reads: "Unless and except as permitted by regulations made as hereinafter provided in this subchapter, it shall be unlawful at any time, by any means or in any manner, to pursue, hunt, take, capture, kill, attempt to take, capture, or kill, possess, offer for sale, sell, offer to barter, barter, offer to purchase, purchase, deliver for shipment, ship, export, import, cause to be shipped, exported, or imported, deliver for transportation, transport or cause to be transported, carry or cause to be carried, or receive for shipment, transportation, carriage, or export, any migratory bird, any part, nest, or egg of any such bird, or any product, whether or not manufactured, which consists, or is composed in whole or part, of any such bird or any part, nest, or egg thereof, included in the terms of the conventions between the United States and Great Britain for the protection of migratory birds concluded August 16, 1916 (39 Stat. 1702), the United States and the United Mexican States for the protection of migratory birds and game mammals concluded February 7, 1936, the United States and the Government of Japan for the protection of migratory birds and birds in danger of extinction, and their environment concluded March 4, 1972, and the convention between the United States and the Union of Soviet Socialist Republics for the conservation of migratory birds and their environments concluded November 19, 1976."

Three things in that sentence matter under a solar array. The verbs include "take" and "possess" but not "destroy", which is why the nest rules below turn on how the regulations define take. The opening clause makes every exception a matter of regulation, so a permit or a regulatory authorization is the only door. And the protected thing is limited to birds "included in the terms of" the four conventions, which the regulations translate into a species list.

Subsection (b), added by the Migratory Bird Treaty Reform Act of 2004 (Public Law 108-447, division E, title I, section 143), sets the limit on introduced species. Paragraph (1) reads: "This subchapter applies only to migratory bird species that are native to the United States or its territories." Paragraph (2) defines native as occurring in the United States or its territories "as the result of natural biological or ecological processes", and says a species that occurs solely as a result of intentional or unintentional human-assisted introduction is not native unless all three of these are true: it was native to the United States or its territories and extant in 1918; it was extirpated after 1918 throughout its range in the United States and its territories; and after that extirpation it was reintroduced as part of a program carried out by a Federal agency. The same act told the Secretary of the Interior to publish "a list of all nonnative, human-introduced bird species to which the Migratory Bird Treaty Act (16 U.S.C. 703 et seq.) does not apply", and allowed updates "as necessary".

The penalty sits in section 707(a): "Except as otherwise provided in this section, any person, association, partnership, or corporation who shall violate any provisions of said conventions or of this subchapter, or who shall violate or fail to comply with any regulation made pursuant to this subchapter shall be deemed guilty of a misdemeanor and upon conviction thereof shall be fined not more than $15,000 or be imprisoned not more than six months, or both." Subsection (b) of the same section, which makes taking a bird with intent to sell it a felony, is not the situation of a homeowner clearing a nest.

How the regulations turn "species" into a legal test

Title 50 of the Code of Federal Regulations, section 10.12, defines the protected object: "Migratory bird means any bird, whatever its origin and whether or not raised in captivity, which belongs to a species listed in § 10.13, or which is a mutation or a hybrid of any such species, including any part, nest, or egg of any such bird, or any product, whether or not manufactured, which consists, or is composed in whole or part, of any such bird or any part, nest, or egg thereof." The same section defines the verb: "Take means to pursue, hunt, shoot, wound, kill, trap, capture, or collect, or attempt to pursue, hunt, shoot, wound, kill, trap, capture, or collect. (With reference to marine mammals, see Part 18 of this subchapter.)" So a nest is protected only as part of a bird of a listed species, and the test for any bird on your roof is whether its species appears in section 10.13.

Section 10.13 is the List of Birds Protected by the Migratory Bird Treaty Act. The current eCFR text, up to date through October 30, 2026, shows its last amendment as 88 FR 49317 (July 31, 2023), the rule that took effect August 30, 2023 and put the total at 1,106 species. On October 1, 2026 the Service proposed another revision (91 FR 62411) that would add 32 species, remove 7 and raise the total to 1,131, with comments open until November 30, 2026. It is a proposal only. Every protected species in the table below stays on the proposed list under its current name or its updated taxonomy, and the proposal adds none of the unlisted species in that table.

Section 10.13 lists only what is protected. What is outside the Act comes from two places. The first is the nonnative list the Service published under the 2004 law: a notice of April 16, 2020 (85 FR 21262) arranging 122 species by family, corrected on May 3, 2021 (86 FR 23422) to remove the European robin, which is protected, leaving 121. The notice says plainly that it "is strictly informational" and that "the presence or absence of a species on this list has, by itself, no legal effect"; the legal effect comes from the statute and from section 10.13. The second place is the set of bird families that the treaties do not name. The notice closes with this paragraph: the Act does not apply to "species native or nonnative to the United States or U.S. territories that either belong to families or groups not referred to in the Canada, Mexico, and Russia Conventions or are not included by species name in the Japan Convention", which "includes" among others "Sturnidae (starlings, except as listed in Japanese treaty), Ploceidae (weavers), Estrildidae (estrildid finches), and Passeridae (Old World sparrows, including house or English sparrow)".

That is why the popular shorthand, "three unprotected species", undercounts. House sparrows and European starlings are outside the Act because of their families. Rock pigeons are outside it because the 2020 notice lists Columba livia among the nonnative Columbidae. The same notice lists the Eurasian collared-dove and the spotted dove, which means the rule that sorts doves under a roof is not "pigeons yes, doves no".

Where the birds in this guide stand on the federal list

The table lists the birds this guide uses as examples, with the unlisted doves and sparrows that cause the identification mistakes, and the wrens, other swallows and the mockingbird as further examples of listed species. "Listed" means the species appears in the alphabetical table at 50 CFR 10.13(c)(1).

Two pairs cause most of the identification risk, and both run in the dangerous direction. A house finch is protected and a house sparrow is not; the "Sparrow" group in the alphabetical table lists 35 species, and the house sparrow is not one of them, so a sparrow-colored bird at a nest is only unprotected if it really is that species. A mourning dove is protected and a Eurasian collared-dove is not, although both are doves. Under the Service's nest memorandum, quoted in a later section, the person who destroys the nest carries the burden of knowing which it is.

The notice also leaves a door open that the shorthand misses. It says a species' appearance on the nonnative list "does not preclude its addition to the list of migratory birds protected by the MBTA (50 CFR 10.13) at some later date should evidence come to light confirming natural occurrence in the United States or U.S. territories." The rows above are the status on the dates in the caption.

The rule written for birds on buildings stops at the interior

The Service added one regulatory authorization aimed at birds in structures: 50 CFR 21.14, part of the rule published December 31, 2024 (89 FR 107026). Paragraph (a) reads in full: "Any person may, without a permit, humanely remove a migratory bird from the interior of a residence, business, or similar building or structure where people live or work under the conditions set forth in this section. Authorization is limited to when the presence of migratory birds is preventing the normal use of the interior of a building or structure, such as causing a health or safety risk to humans or birds or damage to property such as foodstuffs or products for sale, or if the bird may become injured because it is trapped. This authorization does not apply to birds or nests on the exterior of buildings, such as siding or eaves, or to structures that are not human-occupied, such as bridges."

Paragraph (b)(3), the only place the section mentions nests, reads in full: "Nests. You may remove nests, eggs, and nestlings from the interior of a human-occupied building or structure. When possible, prevent the need for take of occupied nests by waiting until nestlings fledge. You may transport eggs or nestlings to a federally permitted migratory bird rehabilitator, if the rehabilitator recommends that you do so. Otherwise, you may humanely destroy eggs or euthanize nestlings following the American Veterinary Medical Association Guidelines for the Euthanasia of Animals or an equivalent process." The older paragraph at 50 CFR 21.12(d) is also an interior rule: it opens "Any person may remove a migratory bird from the interior of a building or structure under certain conditions", and its tenth condition says that if an active nest with eggs or nestlings is present, you must seek the help of a federally permitted migratory bird rehabilitator.

An array is bolted to the outside of the roof. Section 21.14(a) names siding and eaves as its examples of the exterior and does not mention solar equipment, but nothing in the text moves the open space under a roof-mounted module into the building interior. The practical reading is that neither regulation authorizes a homeowner, a roofer or a solar crew to destroy a nest that holds eggs or nestlings under a rooftop array. Even indoors, paragraph (b)(3) tells the owner to wait for fledging when possible, and paragraph (b)(4) requires exclusion devices that "must be regularly monitored, maintained, and repaired to ensure they remain effective and to prevent entrapment, injury, or death". That second duty is a fair model for what a rooftop mesh needs even where no rule requires it, a point the procedure section returns to.

The Service's January 2025 nest memorandum: in-use, inactive, and relocated

The rule that does cover a rooftop nest is a policy document: Migratory Bird Permit Memorandum MBPM-2-02, "Authorizations to take migratory bird nests and contents", dated January 15, 2025 and signed by Jerome Ford, Assistant Director for Migratory Birds. It cites its 2003 and 2018 predecessors and states that it "does not supersede or apply to other relevant Federal, State, or Tribal laws and regulations, including the Endangered Species Act" and the Bald and Golden Eagle Protection Act. Its two definitions are the ones that decide a roof case. "In-use nest: a nest that contains viable eggs or nestlings. A nest becomes in-use when the first egg is laid and remains in-use until nestlings fledge and are no longer dependent on the nest. In-use nests were previously called 'active' nests." And: "Inactive nest: a nest that does not contain viable eggs or nestlings. Nests that are being built or tended by adult birds prior to an egg being laid are considered inactive. Nests are also considered inactive once nestlings fledge and are no longer dependent on the nest. Inactive nests include unattended nests, even if non-viable eggs or nestling remains are present."

Policy 1 reads: "An inactive nest can be destroyed without a permit, or other MBTA authorization, provided no person retains possession of the nest or its contents, including, non-viable eggs or deceased birds or chicks. Relocation of an inactive nest requires authorization as the relocation process requires a person to collect and be in possession of the nest." The memorandum's justification is: "The MBTA specifically protects migratory bird nests from possession, sale, purchase, barter, transport, import, export, and take. Within the regulatory definition of take, only the term 'collect' could apply to the nest itself. Because the MBTA does not prohibit the destruction of a migratory bird nest alone, a permit or other regulatory authorization is not required to destroy a nest that is inactive."

Then comes the sentence that puts the risk on the person holding the tool. Under "Individual Responsibility": "It is the responsibility of the individual destroying an inactive nest to ensure the take of migratory birds, nestlings, or viable eggs will not occur. While the destruction of a nest by itself is not prohibited under the MBTA, nest destruction that results in unpermitted take of migratory birds, nestlings, or viable eggs, is illegal and fully prosecutable under the MBTA. Nesting behaviors of many migratory bird species can make it difficult to determine whether a nest is in use. The biological and behavioral characteristics of some migratory bird species can increase the risk of an MBTA violation for taking an in-use nest, particularly colonial nesting species, burrowing species, and secretive species. It is the responsibility of the individual conducting activities intended to or likely to destroy the nest to ensure that the nest is inactive and that destroying it will not take migratory birds, viable eggs, or chicks. We recommend conducting activities outside of nesting season because doing so reduces the risk of take."

Under "Additional Protections" the memorandum adds: "Even when inactive, migratory bird nests may be protected by additional Federal, State, Tribal, and local laws", with the federal examples being the inactive nests of bald and golden eagles and of listed species that are also on the Endangered Species Act list at 50 CFR 17.11, and then: "It is the responsibility of the individual to determine whether there are additional protections and restrictions prior to destroying an inactive nest." That sentence is the only sourced basis here for checking state and local rules, and no state statute is reviewed in this guide.

Policy 2 closes the loop: "Take of In-Use Nests: Destruction of an in-use nest requires MBTA authorization. MBTA authorization is also required to relocate a nest, whether the nest is in-use or inactive. This is because relocation of a nest requires collection and possession of the nest. Destruction of an in-use nest or relocation of any nest requires compliance with MBTA regulations and, if a permit is required, any conditions attached to the permit." Moving a nest to a box or a tree involves possession of it and needs authorization even when it is empty, and keeping the removed nest or a bag of its contents is retaining possession in the memorandum's own wording. The nest of an unlisted species falls outside all of this, because for it the Act itself does not apply.

If the nest is in use: the permit routes, the fees and the clock

Policy 2 points to three routes: research permits (50 CFR 21.73), depredation permits (subpart D) and special purpose permits (21.95). Research does not fit a roof. The other two are the realistic ones. Section 21.95 opens: "Permits may be issued for special purpose activities related to migratory birds, their parts, nests, or eggs, which are otherwise outside the scope of the standard form permits of this part. A special purpose permit for migratory bird related activities not otherwise provided for in this part may be issued to an applicant who submits a written application containing the general information and certification required by part 13 and makes a sufficient showing of benefit to the migratory bird resource, important research reasons, reasons of human concern for individual birds, or other compelling justification." A special purpose permit issued under part 21 expires on the date on its face and in no case runs longer than three years. Section 21.100(a) is the depredation rule: "Except as provided in §§ 21.150, 21.153, and 21.156, a depredation permit is required before any person may take, possess, or transport migratory birds for depredation control purposes. No permit is required merely to scare or herd depredating migratory birds other than endangered or threatened species or bald or golden eagles." Depredation permits last no longer than one year, and permittees may not kill migratory birds unless the permit specifically allows it.

The three sections cited in 21.100(a) are crop-protection orders. Section 21.150 covers blackbirds, cowbirds, crows, grackles and magpies. Section 21.153 lets horned larks, house finches and white-crowned sparrows be taken in Fresno, Merced, Napa and Sonoma Counties in California when they are depredating on agricultural or horticultural crops, under the county agriculture commissioner. Section 21.156 covers California scrub jays and Steller's jays on nut crops in named Washington and Oregon counties. Neither 21.153 nor 21.156, the two whose text is quoted here, is a nest-removal authorization for a homeowner. The memorandum adds that the Service "will ensure that permit requests for nest destruction are for situations where it is necessary and consistent with the MBTA and its governing regulations", and that the Migratory Bird Permit Office "can assist in determining the correct permit type or regulatory authorization".

The fee schedule at 50 CFR 13.11(d)(4), as of October 30, 2026, lists a Migratory Bird Special Purpose/Miscellaneous permit at $100, a Migratory Bird Depredation permit at $100 and a Migratory Bird Depredation/Homeowner permit at $50. Section 13.11(c) asks applicants to postmark applications for permits other than marine mammal and endangered species permits "at least 60 calendar days prior to the requested effective date" and adds that the Service "cannot guarantee final action within the time limit you request."

Set that 60 days beside the nest cycles in the next section. The in-use period of a house finch, mourning dove, European starling or barn swallow nest, counted from the start of incubation to the day nestlings leave, runs from 24 to 34 days in the sources used here, and the laying days before incubation add to it. A fee-and-paperwork route with a 60-day request window will usually arrive after the birds have gone, which is why this guide treats a permit as a route for a nest that creates a real hazard and not for one that is merely in the wrong place.

Nest cycles in days, and what a calendar can and cannot tell you

A nest is in use for far longer than the nestling stage, and it comes back. The memorandum counts a nest as in use from the first egg until the young are no longer dependent on it. The table gives the published incubation and nestling figures for the species the sources cover; the last column adds the two to give the shortest in-use stretch of a single brood, because laying days and any post-fledging dependence come on top.

Two rows end the idea of a universal calendar. A rock pigeon can have eggs on any date in Texas, and a mourning dove nest can be in use in any month there, so for those two the only reliable test is the nest, not the month. For the rest the window is long: Texas starlings were carrying nest material for 143 days (March 18 to August 8) and house finch eggs were collected across 139 days (March 18 to August 4). A house sparrow nest in one Texas county held eggs from March 18 to mid-August, about 150 days. Regions further north start later and end earlier, as the Pennsylvania entries show, but the Penn State text gives months, not dates.

What the memorandum asks is the opposite of a calendar rule. The individual must "ensure that the nest is inactive", and a nest that has gone quiet for a week can still be a second-brood site: the Texas atlas says house finches "may reuse nests for a second brood in the same or another year", and for house sparrows that nests "are commonly used from year to year". The working rule is therefore two parts. Use the calendar to decide when to start looking, and use observation of the nest itself to decide when it is inactive, with dated photographs as the record.

One June house finch nest, dated

A house finch pair builds under row two of an array in Texas, and on June 3 the owner photographs a female sitting on a nest with eggs. The date incubation began is unknown, so every date computed from June 3 is the earliest possible, not a promise. Incubation of 12 to 14 days puts hatching between June 15 and June 17. Nestlings leaving 12 to 15 days after hatching puts fledging between June 27 and July 2, the 24 to 29 days in the table counted from June 3. A permit request postmarked June 3 under the 60-day window in 50 CFR 13.11(c) would be asking for an effective date of August 2 at the earliest, a month after the birds have gone.

The owner therefore waits and watches. The nest is in use until the young leave and stop depending on it, so the earliest the owner can start to treat it as inactive is early July, and the Texas atlas shows house finch eggs collected until August 4, so a second brood in the same nest is still plausible. If the visits on July 3, July 10 and July 17 show no adults carrying material or food, the owner photographs each visit, removes and discards the nest on July 17, cleans the spot and has the mesh fitted. If a bird of the same species is carrying grass on July 10, the clock restarts and the record shows why. A house sparrow nest in the same spot would raise none of these questions under the Act, though the owner would still need to check state and local rules, which this guide does not review.

Clearing an inactive nest and closing the gap: the order of work

The sequence follows from the memorandum's definitions and from the one duty that 21.14(b)(4) states for buildings, that exclusion devices must be monitored and must not trap or kill. Everything below is practice built on those texts, not a regulatory checklist.

1. Name the bird before touching anything. Photograph the adults and the nest from the ground with a zoom lens, then match the species against the table above. If it could be either a house sparrow or a house finch, or either a collared-dove or a mourning dove, treat it as the protected one until a state wildlife agency or a federally permitted rehabilitator confirms the species.
2. Decide whether the nest is in use. The definition is viable eggs or nestlings, from the first egg until the young no longer depend on the nest. Watch from a distance on at least two days a few days apart, at different hours. Adults carrying food in, begging calls from under the module, or an adult that stays put are signs of an in-use nest. Do not lift a module edge or reach under the array to check; the memorandum itself warns that the nesting behavior of many species "can make it difficult to determine whether a nest is in use".
3. Wait for the young to leave and stay gone. Use the cycle table for the earliest date, then add a margin. Several quiet visits over a week or more, with no adults carrying material, is a reasonable record that the nest has gone from in use to inactive. If the species is on the table and a second brood is plausible for your region and date, assume it, because the atlas says reuse happens.
4. If the nest is still being built and holds no egg, it is inactive under the memorandum's second definition. Removing nest material at that stage is the cleanest moment legally, but the individual still carries the burden of being sure that no egg has been laid, which a gap under a module makes hard to confirm. Where you cannot see in, wait.
5. Remove the nest and keep nothing. Policy 1 allows destruction only if no person retains possession of the nest or its contents, and Policy 2 requires authorization to relocate a nest. Bag the material, dispose of it and do not give the nest, an egg shell or a feather to a neighbor or a school. Do not move it to a nest box.
6. Clean before you close. Droppings and nest debris under an array are a hazard of their own (next section), and a mesh fitted over fouled material holds it against the roof.
7. Fit the exclusion, then verify it is empty. The goal is a barrier along every open edge that a bird can use, fixed so it stays in place in wind and does not rub the wiring. Before the last section is closed, look for any bird inside the gap and any sign that one went in that morning. A protected bird sealed in under an array is trapped, and trapping is take as section 10.12 defines it.
8. Inspect the mesh on a schedule. Section 21.14(b)(4) tells building owners that exclusion devices must be regularly monitored, maintained and repaired "to ensure they remain effective and to prevent entrapment, injury, or death". The same logic applies on a roof: look at the edge once before nesting begins, and again after storms.

Some of this belongs to the installer. If your array is owned, the crew that fits a mesh skirt is doing a small scope of work, the sort of line the adders and change orders guide tells you to ask for by linear footage, and the maintenance guide places in the yearly inspection. If the panels have to come down for a new roof, the removal and reinstall cost guide notes that a perimeter barrier is far easier to fit while the array is off the roof. In every case the memorandum puts the burden on whoever is "conducting activities intended to or likely to destroy the nest", so a contract that says the crew will check for in-use nests before work is worth asking for in writing. If you lease the system or buy its power, the array belongs to someone else, and the first call is to them.

Records that settle a later question

• Dated photographs of the adults and the nest, taken from the ground, with the species you concluded it was and why.
• At least three dated observations, spaced a few days apart, showing no adult carrying food or nest material to the nest.
• The date the young were last seen or heard, and the date you judged the nest inactive.
• A note that the nest and its contents were disposed of and that nothing from it was kept or moved elsewhere.
• A photograph of the gap empty before the mesh was closed, and the installer's work order showing the edge length and the date.
• The state and local wildlife rules you checked before removal, or a note that you asked the state wildlife agency.

Droppings under the array: the clean-up step

The Centers for Disease Control and Prevention (page dated April 24, 2024) explains that histoplasmosis is a lung infection caused by breathing in spores of the fungus Histoplasma, which "lives in soil" and "also spreads in bird and bat droppings that mix in soil", and that in the United States it lives mainly in the central and eastern states. Symptoms usually appear 3 to 17 days after exposure. Its prevention page lists "Cleaning, remodeling, or tearing down old buildings" among the activities that raise risk, advises avoiding activities that disturb soil that contains bird or bat droppings, and says: "Large amounts of bird or bat droppings should be cleaned up by professional companies that specialize hazardous waste removal." For construction workers it gives the example of protective masks "like N-95s".

The CDC pages concern soil-mixed droppings and buildings generally, not roof arrays, so they do not say what quantity under a module counts as large. The page's own example for workers is an N-95 mask, and its instruction for large amounts is a professional company, so a roofer or installer facing years of accumulated droppings is in the second category, and a small amount is the owner's judgment. Fouling is also a production issue. The guide to solar producing less than expected describes what one shaded or dirty module looks like in the monitoring data, a reason to wash the glass edge after the nest is gone.

What closing the gap costs on the federal benchmark model's labour lines

The U.S. Department of Energy's Q1 2025 residential benchmark is $2.95 per watt DC for an 8 kW PV-only system, $23,600 in 2024 dollars (Table 2 of the benchmark page, checked November 3, 2026; the cost per watt guide explains the line), built from a public cost model that the National Laboratory of the Rockies maintains. The model has no line for animal exclusion, so the material is outside it. What it does carry is the cost of fieldwork labour, including burden, and from those lines an hourly rate can be backed out. Structural labour (roof assessment, racking installation, module mounting) is $19.43 per square metre at "0.3 hour/m2 typical", an implied $64.77 per labour hour. Electrical labour is $109 per kW of AC capacity at 2 hours per kW, an implied $54.50 an hour, which does not apply because a mesh skirt touches no wiring. Site management is $147.60 fixed plus $0.886 per square metre at 1.5 hours, an implied $98.40 an hour. The model adds developer profit at 15 percent of its subtotal. Its array is 20 modules of 400 watts at 0.204 kW per square metre, about 39.2 square metres.

To turn that into a mesh job, three assumptions are printed here as assumptions and are not model data. First, a module of 1.72 by 1.14 metres (1.96 square metres, which matches the model's area), laid out as two rows of ten in portrait. That makes the array 11.4 metres wide and 3.44 metres tall. Second, a crew fits 5 metres of mesh an hour at the structural rate, with 8 and 3 metres an hour as the fast and slow cases. The model prices racking by area, not by the metre, so no published rate exists for this. Third, the work either rides on a visit already booked, which pays labour plus profit, or needs its own trip, which adds the model's site-management line ($182 for this array) before profit.

At the middle productivity, closing all four sides while another crew is already on the roof comes to $442 of labour, 1.9% of the $23,600 benchmark price or $0.055 per watt; the same job as a separate trip is $652, 2.8% or $0.082 per watt. A lower edge and both sides is $272 on a visit already booked and $482 as its own trip. The lower edge alone is $170 and $380. Mesh and fasteners are not in these figures. Ask for them as a separate priced line with a stated length, as the adders guide recommends, and compare the footage on the quote with the edge length in the table: all four sides of this array is 97 feet.

These are labour proxies for an easy, unobstructed edge, not quotes. A steep or two-storey roof, an array with tight tolerances to the roof edge, tile roofs and arrays on ballasted flat roofs would all change the hours. The use for these numbers is reading a quote: a written price far above these ranges needs its footage, its trip charge and its materials itemized.